Vehicle frames typically have one or more parallel chassis rails or other frame members which provide structural support for the vehicle, and a “C-channel” or other hollow extrusion may typically be used to form each chassis rail or other frame member. The components of various vehicle systems are mounted to the vehicle frame. For example, in a typical electric traction vehicle, system components such as an engine, generator, mechanical system components, electrical traction motors and other electrical system components, fuel tank, coolant tanks, hydraulic system components, etc. need to be mounted to the vehicle frame The limited space between the chassis rails and other vehicle frame members is often used for routing the many required interconnections between components, such as electrical wiring, mechanical linkages, exhaust piping, piping or hoses for fluids such as hydraulic oils or coolants, etc. Depending upon the number of system components and the required interconnections between these components, the usable space between the chassis rails and other vehicle frame members may quickly become overcrowded, making assembly of and access to the various components and interconnections increasingly difficult. Routing the interconnections between the chassis rails or other vehicle frame members may also leave the interconnections exposed to damage or excessive wear that can decrease system reliability. Further, exposed routings of high voltage electrical connections, such as a 480 Volt connection between a generator and a traction motor on an electric traction vehicle may create electrical safety hazards. Thus, it would be beneficial to provide a vehicle frame that is configured to facilitate the routing of interconnections between vehicle system components in the usable space within each frame member in order to conserve space and provide a protected routing path for the various system interconnections.
In addition, many vehicle system components generate large amounts of heat that must be dissipated during operation. For example, on a typical electric traction vehicle, a diesel engine, electrical traction motors, axle assemblies, and electronic motor controllers may all be interconnected to a cooling system that circulates a coolant fluid during operation of the vehicle to dissipate the heat generated by these components. Other vehicles may include hydraulic systems that require cooling of a hydraulic fluid during operation. The size and cost of these cooling systems increases with the amount of heat generated by these components. Thus there is further need for a vehicle frame that is configured to facilitate the transfer and cooling of a fluid between a fluid source and various heat-generating vehicle system components in order to reduce the required size and cost of the cooling system.